The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides a method and apparatus for perforating and isolating perforations in a wellbore.
Occasionally it is desired to perforate one or more zones in a well after one or more other zones have already been perforated. The previously perforated zone(s) would be isolated, allowing production or injection to proceed via the newly perforated zone(s).
Typically, this would be accomplished by conveying perforating guns into the well to perforate the additional zones, and then conveying straddle packers into the well to isolate the originally perforated zones. It will be appreciated that this method requires multiple trips into the well, requires that the straddle packers be conveyed into the well and set after perforating debris has been introduced into the well, and allows cross-flow between the originally perforated zones and the newly perforated zones in the time between when the perforating guns are detonated and when the straddle packers are set. This cross-flow may be an environmental hazard or at least a waste of valuable resources.
Therefore, it may be seen that improvements are needed in the art of well perforating and isolation.